Typing improvements and loosened dependencies

[Zaczero]

This PR is a set of several typing improvements as well as loosened dependencies which resolves #341. While this PR bundles several changes, the commits are atomic and should be simple to review individually.

More notable changes:

• pydantic depdendency was replaced with pydantic-settings as in official docs.
• set_json_dumps no longer uses a .decode() wrapper method, since bytes return is supported in psycopg since 3.1.9.
• pathlib.Path type hints were removed since from my testing they never worked (they are not an instance of str).